Hitherto, a method using the human body as a transmission path and transmitting and receiving video signals by contact has been known (Japanese Unexamined Patent Application Publication No. 7-170215). In this method, a signal communications path is formed with the human body, which is an electrical conductor, as a main communications path and an electromagnetic near field as a return communications line.
The inventors of the present invention have further developed the foregoing technology and have conducted research so that information can be exchanged using ionizable liquid as the main communications line, resulting in the present invention.